I have an odd problem that as of yet I have been unable to isolate. We've begun to see that random emails seem to get stuck somewhere and are suddenly sent out when we restart our Windows SBS 2003 server running Exchange SP2. When we haven't restarted for a month or two, we've seen emails sent out that are up to two months old. There is no pattern. There are some people that I may send 4 emails a day and when we restart they mention that a couple of old emails suddenly appear that were never sent . It therefore isn't an isse of an undeliverable address. Other users have reported similar scenarioes after we restart.
It is difficult to give an accurate assessment of how often this happens but I suspect that it is less than 5% of the emails and i likely less than 1% of the emails we send. Unfortunately if the one that gets stuck is important and we don't get any notifcation of a problem we assume it was sent.
Has anyone seen anything like this before and / or do you have any suggestions on what might be causing this and how I might go about tracking and correcting the issue.
For now I've resorted to restarting the server once a week in order to flush out the stuck emails more often.